Heterogeneous processes in chemistry and biotechnology encompassing a solid member (including, but not limited to, immobilized chemical reagent, catalyst, scavenger, reaction support, or trapping sorbent, or immobilized biological materials such as cells or fragments thereof) contacting a fluidic medium carrying reactants or other agents, sample solutes, and/or products of the interactive processing of fluid-conveyed agent(s) with the solid member(s) are critically dependent on convective flow to accomplish the necessary mass transfer between the two phases. Such systems are therefore often operated in a continuous flow through mode, in which case a conventional packed column with a suitable design is often the preferred format for encapsulating the solid member that is to be transited or percolated by the reaction medium. Numerous processes are, however, unfit for continuous processing. This applies in particular to processes where sequential addition of agents and/or removal of by-products or desired products are necessary, or where the physical or chemical conditions must otherwise be altered during the course of processing with the solid member. In those cases a batch-wise processing mode is often preferred. Such batch-wise heterogeneous processing can either be done by suspending the solid member directly in the fluidic medium as particulate material under agitation, a process that will normally call for a filtration or sedimentation step to separate the phases after the process has been brought to an end. Alternatively, the fluidic medium can be circulated from the batch reactor through a packed reservoir containing the solid member by means of a specially designed flow system comprising pumps and/or valves or the like, in order to accomplish the convective mass transfer needed for the reactions to take place. Such reactors are often quite complicated and must regularly be built for the specific purpose.
The challenge of establishing efficient convective mass transfer between solid and fluidic phases has been addressed, e.g., by applying the solid member as a coating on the external surface of a rotating device (E. Baltussen, et al., J. Microcolumn Separations, 11 (1999) 737-747; U.S. Pat. No. 6,815,216), as well as on the inside of narrow tubes coated with solid member through which the fluidic medium is conveyed by conventional pumping (R. Eisert, J. Pawliszyn, Anal. Chem., 69 (1997) 3140-3147; U.S. Pat. No. 5,691,206). While these products may be fit for the analytical sampling purposes for which they were designed, the amount of solid member that can be incorporated will be severely limited in systems where only the external or internal surface has been modified to act as the solid member. Further, since the surface area does not increase linearly with the volume of a reactor where the solid member is deposited on the surfaces only, such systems are also not well suited for up-scaling.
U.S. patent application publication no. 2007/0189115 discloses a hollow magnetic stirrer designed to create an internal flow when rotated. The stirrer is not designed to house any solids for performing biological or chemical transformation, or physical or chemical trapping.
U.S. Pat. No. 6,857,774 B2, representing the closest prior art, discloses a device for cavitational mixing and pumping. This performance of the device described in this piece of prior art is partially based on the same principles as the device of the present invention, i.e., the generation of a flow using a centripetal force field. However, the devices according to U.S. Pat. No. 6,857,774 B2 do not comprise a confinement which can house a solid member for carrying out the transformation and/or trapping actions that are the scope of the invention disclosed here, and the purpose of the devices described in the prior art is fundamentally different, namely to promote cavitation to establish sonochemical reaction conditions in homogeneous solution.